Vinyl group-containing prepolymer and curable resin composition

Abstract

Provided is a vinyl group-containing prepolymer having excellent dielectric properties. A vinyl group-containing prepolymer according to an embodiment includes a first moiety derived from a hydride of a conjugated diene polymer polyol, a second moiety derived from at least one polyisocyanate selected from an aliphatic polyisocyanate and an alicyclic polyisocyanate, and a third moiety derived from a hydroxyl group-containing aromatic vinyl compound. The first moiety and the second moiety are bonded via a urethane bond formed by a reaction between a hydroxyl group of the hydride and an isocyanate group of the polyisocyanate. The second moiety and the third moiety are bonded via a urethane bond formed by a reaction between an isocyanate group of the polyisocyanate and a hydroxyl group of the hydroxyl group-containing aromatic vinyl compound.

Description

Technical Field

[0001] Embodiments of the present invention relate to a vinyl group-containing prepolymer, a curable resin composition containing the vinyl group-containing prepolymer, and a cured product thereof. Background Art

[0002] As a curable composition that can be cured by heat or the like, a thermosetting resin composition comprising a vinyl-containing prepolymer obtained by reacting an organic isocyanate compound with a hydroxyl-containing aromatic vinyl compound, and a vinyl monomer is disclosed in Patent Document 1. As an example thereof, Patent Document 1 discloses a prepolymer having a vinyl group at a terminal, which is obtained by reacting 1 mol of polybutadiene diol with 2 mol of 1,3-phenylene diisocyanate and further reacting 2 mol of hydroxyethyl styrene.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Publication No. 52-43514 Summary of the invention

[0006] Technical problem that the invention aims to solve

[0007] However, it was found that the vinyl group-containing prepolymer described in Patent Document 1 has insufficient dielectric properties when used in applications utilizing high-frequency electric signals, for example.

[0008] An object of an embodiment of the present invention is to provide a vinyl group-containing prepolymer having excellent dielectric properties.

[0009] Technical solutions to the problem

[0010] The present invention includes the following embodiments.

[0011] [1] A vinyl group-containing prepolymer comprising: a first part derived from a hydrogenated product of a conjugated diene polymer polyol; a second part derived from at least one polyisocyanate selected from an aliphatic polyisocyanate and an alicyclic polyisocyanate; and a third part derived from a hydroxyl-containing aromatic vinyl compound, wherein the vinyl group-containing prepolymer has a vinyl group at a terminal, and the vinyl group-containing prepolymer has a structure in which the first part and the second part are bonded via a urethane bond formed by a reaction between a hydroxyl group of the hydrogenated product and an isocyanate group of the polyisocyanate, and the second part and the third part are bonded via a urethane bond formed by a reaction between an isocyanate group of the polyisocyanate and a hydroxyl group of the hydroxyl-containing aromatic vinyl compound.

[0012] [2] The vinyl-containing prepolymer according to [1], wherein the number average molecular weight of the hydrogenated product of the conjugated diene polymer polyol is 500 to 5,000.

[0013] [3] The vinyl group-containing prepolymer according to [1] or [2], wherein the hydrogenated product of the conjugated diene polymer polyol is a hydrogenated polybutadiene polyol and / or a hydrogenated polyisoprene polyol.

[0014] [4] The vinyl-containing prepolymer according to any one of [1] to [3], wherein the hydroxyl-containing aromatic vinyl compound is a compound represented by the following general formula (1), wherein R 1 represents an alkanediyl group having 1 to 4 carbon atoms, R 2 represents an alkyl group having 1 to 4 carbon atoms, and p represents an integer of 0 to 4.

[0015] [Chemistry 1]

[0016]

[0017] [5] A curable resin composition comprising the vinyl group-containing prepolymer according to any one of [1] to [4].

[0018] [6] The curable resin composition according to [5], which is used for a high-frequency insulating material.

[0019] [7] A cured product obtained by curing the curable resin composition according to [5] or [6].

[0020] Effects of the Invention

[0021] According to the embodiment of the present invention, a vinyl group-containing prepolymer having excellent dielectric properties can be provided. DETAILED DESCRIPTION

[0022] The vinyl-containing prepolymer of the present embodiment is a prepolymer having a vinyl group at the terminal. Here, the prepolymer refers to a substance in the pre-stage of becoming a polymer, and refers to a substance showing curability that can be cured by polymerization or crosslinking reaction using heat, light, etc.

[0023] The vinyl-containing prepolymer of the present embodiment includes: a first part derived from a hydrogenated product (A) of a conjugated diene polymer polyol; a second part derived from at least one polyisocyanate (B) selected from an aliphatic polyisocyanate and an alicyclic polyisocyanate; and a third part derived from a hydroxyl-containing aromatic vinyl compound (C). In addition, the vinyl-containing prepolymer has a structure in which the first part and the second part are bonded via a urethane bond formed by a reaction between a hydroxyl group of the hydrogenated product (A) and an isocyanate group of the polyisocyanate (B), and the second part and the third part are bonded via a urethane bond formed by a reaction between an isocyanate group of the polyisocyanate (B) and a hydroxyl group of the hydroxyl-containing aromatic vinyl compound (C). Therefore, the vinyl-containing prepolymer has a urethane bond in addition to a vinyl group.

[0024] In one embodiment, the vinyl-containing prepolymer is formed by reacting the hydroxyl group of the hydroxyl-containing aromatic vinyl compound (C) with the above-mentioned isocyanate group of the primary product (D) having an isocyanate group, and the primary product (D) having an isocyanate group is formed by reacting the hydride (A) of the conjugated diene polymer polyol with at least one polyisocyanate (B) of an aliphatic polyisocyanate and an alicyclic polyisocyanate. However, this description is not intended to limit the synthesis method of the vinyl-containing prepolymer. For example, after reacting the above-mentioned hydride (A) with the polyisocyanate (B), the hydroxyl-containing aromatic vinyl compound (C) is reacted with the obtained product. Alternatively, after reacting the polyisocyanate (B) with the hydroxyl-containing aromatic vinyl compound (C), the above-mentioned hydride (A) is reacted with the obtained product.

[0025] The hydrogenated product (A) of the conjugated diene polymer polyol has a structure obtained by hydrogenating the conjugated diene polymer polyol. The conjugated diene polymer polyol has a structure obtained by introducing a hydroxyl group into a conjugated diene polymer obtained by polymerizing a conjugated diene monomer. As the conjugated diene monomer, for example, 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethylbutadiene, etc. can be listed, and any one or more of these can be used. 1,3-butadiene and / or isoprene are preferred. Therefore, as the hydrogenated product (A) of the conjugated diene polymer polyol, hydrogenated polybutadiene polyol and / or hydrogenated polyisoprene polyol are preferred, and hydrogenated polybutadiene polyol is more preferred from the viewpoint of high elongation.

[0026] As the hydrogenated product (A) of the conjugated diene polymer polyol, it is preferred to use one having an average of 1.5 or more hydroxyl groups per molecule, and more preferably 1.6 to 2.5 on average. It is further preferred to use a hydrogenated product of a conjugated diene polymer diol having an average of 1.8 to 2.1 hydroxyl groups per molecule (for example, hydrogenated polybutadiene diol, hydrogenated polyisoprene diol). In this specification, the number of hydroxyl groups per molecule (the number of functional groups) is a value calculated by the following formula.

[0027] Functional group number = {(hydroxyl value) × (Mn)} / (56.1 × 1000)

[0028] In the hydrogenated product (A) of the conjugated diene polymer polyol, the microstructure of the conjugated diene polymer chain constituting the basic skeleton is not particularly limited, and may be a 1,4-bond type, a 1,2-bond type, a 3,4-bond type, or a mixture of two or more thereof. For example, the hydrogenated polybutadiene polyol may have a structure in the molecule in which a polybutadiene polyol having hydroxyl groups at both ends of a polybutadiene structure of a 1,4-bond type, a 1,2-bond type, or a mixture thereof is hydrogenated. In addition, the hydrogenated polyisoprene polyol may also have a structure in the molecule in which a polyisoprene polyol having hydroxyl groups at both ends of a polyisoprene structure of a 1,4-bond type, a 1,2-bond type, a 3,4-bond type, or a mixture thereof is hydrogenated. In one embodiment, in the microstructure of the hydrogenated polybutadiene polyol, the content of the 1,2-bond type is 50 mol% or more, and may also be 50 mol% to 80 mol%. Here, the microstructure may be determined by 13 C-NMR (carbon-13 nuclear magnetic resonance) was used for determination.

[0029] The hydrogenated product (A) of the conjugated diene polymer polyol is obtained by hydrogenating part or all of the unsaturated double bonds contained in the conjugated diene polymer polyol. Therefore, the 1,4-bond type, 1,2-bond type and 3,4-bond type are used to include both hydrogenated and unhydrogenated types.

[0030] In the hydrogenated product (A) of the conjugated diene polymer polyol, the degree of hydrogenation is not particularly limited, and for example, the iodine value may be 40 g / 100 g or less, 30 g / 100 g or less, 25 g / 100 g or less, 15 g / 100 g or less, or 10 g / 100 g or less. In this specification, the iodine value is measured in accordance with Japanese Industrial Standards (JIS) K0070:1992.

[0031] The molecular weight of the hydrogenated product (A) of the conjugated diene polymer polyol is not particularly limited, but the number average molecular weight (Mn) is preferably 500 to 5,000, more preferably 1,000 to 4,500, and even more preferably 1,500 to 4,000.

[0032] In this specification, the number average molecular weight (Mn) is a value calculated by measuring by gel permeation chromatography (GPC (Gel Permeation Chromatography) method) and using a calibration curve based on standard polystyrene. The conditions of GPC are, for example, columns: "Shodex GPC columns KF-601, KF-602, KF-603, KF-604" (4 connected) manufactured by Showa Denko K.K., mobile phase: tetrahydrofuran (THF), mobile phase flow rate of 0.6 mL / min, column temperature of 40°C, sample injection volume of 10 μL, and sample concentration of 0.1% by mass.

[0033] The hydroxyl value of the hydrogenated product (A) of the conjugated diene polymer polyol is not particularly limited, and may be, for example, 10 mgKOH / g to 200 mgKOH / g, 15 mgKOH / g to 120 mgKOH / g, 20 mgKOH / g to 100 mgKOH / g, or 25 mgKOH / g to 80 mgKOH / g. In this specification, the hydroxyl value is measured according to the A method of JIS K1557-1:2007.

[0034] As the polyisocyanate (B), an aliphatic polyisocyanate and / or an alicyclic polyisocyanate is used.

[0035] Examples of the aliphatic polyisocyanate include tetramethylene diisocyanate, dodecamethylene diisocyanate, hexamethylene diisocyanate (HDI), 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 1,5-pentane diisocyanate, 2-methylpentane-1,5-diisocyanate, and 3-methylpentane-1,5-diisocyanate. Any one of these may be used alone or in combination of two or more.

[0036] Examples of the alicyclic polyisocyanate include isophorone diisocyanate (IPDI), dicyclohexylmethane 4,4'-diisocyanate (hydrogenated MDI), hydrogenated xylylene diisocyanate, 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, 1,3-bis(isocyanatemethyl)cyclohexane, etc. Any one of these may be used alone or in combination of two or more.

[0037] As the polyisocyanate (B), from the viewpoint of being able to further reduce the dielectric loss tangent, it is preferred to use an alicyclic polyisocyanate, and isophorone diisocyanate and / or dicyclohexylmethane 4,4'-diisocyanate are more preferred. From the viewpoint of reaction control during synthesis of a vinyl-containing prepolymer, it is further preferred to use isophorone diisocyanate.

[0038] The hydroxyl-containing aromatic vinyl compound (C) is a vinyl compound having a hydroxyl group and an aromatic ring, and preferably one having one vinyl group and one hydroxyl group. As the hydroxyl-containing aromatic vinyl compound (C), a compound represented by the following general formula (1) is preferably used.

[0039] [Chemistry 2]

[0040]

[0041] In formula (1), R 1 represents an alkanediyl group having 1 to 4 carbon atoms. 1 Specific examples of R include methylene, ethylene, propylene, trimethylene, tetramethylene, and ethylethylene. 1 The bonding position of OH to the benzene ring may be the ortho position, the meta position, or the para position relative to the vinyl group.

[0042] In formula (1), R 2 represents an alkyl group having 1 to 4 carbon atoms. 2 Specific examples of include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, and tert-butyl. In formula (1), p represents a substituent R on the benzene ring. 2 The number of is an integer of 0 to 4, preferably an integer of 0 to 2. 2 The bonding position to the benzene ring may be the ortho position, the meta position, or the para position with respect to the vinyl group.

[0043] Examples of the hydroxyl-containing aromatic vinyl compound (C) include 4-vinylbenzyl alcohol, 3-vinylbenzyl alcohol, 2-vinylbenzyl alcohol, p-(2-hydroxypropyl)styrene, p-hydroxyethylstyrene, o-hydroxyethylstyrene, and the like, and any one of these or a combination of two or more thereof may be used. As the hydroxyl-containing aromatic vinyl compound (C), vinylbenzyl alcohol, i.e., at least one vinylbenzyl alcohol selected from the group consisting of 4-vinylbenzyl alcohol, 3-vinylbenzyl alcohol, and 2-vinylbenzyl alcohol, is preferably used.

[0044] The primary product (D) is a compound having an isocyanate group obtained by reacting a hydrogenated product (A) of a conjugated diene polymer polyol with a polyisocyanate (B). For example, by reacting an amount of the hydrogenated product (A) corresponding to 1 mol with 2 mol of the polyisocyanate (B), a primary product (D) having isocyanate groups at both ends can be obtained.

[0045] The reaction of the hydride (A) and the polyisocyanate (B) can be carried out in the absence of a solvent or in an organic solvent. The reaction temperature is not particularly limited, and can be, for example, 10°C to 100°C, or 20°C to 80°C. As the organic solvent, for example, the diluent described later (vinyl monomer having no active hydrogen) can be used. In this case, a polymerization inhibitor that prevents their polymerization can be added. In addition, a known urethanization catalyst can be used during the reaction.

[0046] In one embodiment, the primary product (D) comprises a first portion derived from the hydride (A) and a second portion derived from the polyisocyanate (B), and has a structure in which the second portion is bonded to both ends of the first portion via a urethane bond, and has isocyanate groups at both ends. The urethane bond is formed by the reaction of a hydroxyl group of the hydride (A) and an isocyanate group of the polyisocyanate (B).

[0047] In one embodiment, the vinyl-containing prepolymer is obtained by reacting a hydroxyl group of a hydroxyl-containing aromatic vinyl compound (C) with an isocyanate group of the primary product (D). For example, by reacting an amount of 2 mol of a hydroxyl-containing aromatic vinyl compound (C) with 1 mol of the primary product (D), a vinyl-containing prepolymer having vinyl groups at both ends can be obtained.

[0048] The reaction of the primary product (D) and the hydroxyl-containing aromatic vinyl compound (C) can be carried out without a solvent or in an organic solvent. The reaction temperature is not particularly limited, and can be, for example, 10°C to 100°C, or 20°C to 80°C. As an organic solvent, for example, a diluent (vinyl monomer having no active hydrogen) described below can also be used. In addition, a known urethanization catalyst or an inhibitor for preventing vinyl polymerization can also be added during the reaction.

[0049] The vinyl-containing prepolymer includes the first and second parts and also includes a third part derived from a hydroxyl-containing aromatic vinyl compound (C), and has a structure in which the second part and the third part are bonded via a urethane bond. In one embodiment, the urethane bond is formed by a reaction between an isocyanate group of the primary product (D) and a hydroxyl group of the hydroxyl-containing aromatic vinyl compound (C). The vinyl-containing prepolymer has vinyl groups derived from the hydroxyl-containing aromatic vinyl compound (C) at both ends.

[0050] The vinyl group-containing prepolymer according to one embodiment is represented by the following general formula (2).

[0051] [Chemistry 3]

[0052]

[0053] In formula (2), R 1 , R 2 and p and R in formula (1) 1 , R 2 and p are the same, R at both ends 1 , R 2 and p may be the same or different.

[0054] In formula (2), X represents the residue of the first part, i.e., the hydrogenated product (A) of the conjugated diene polymer polyol, and more specifically, represents the part of the hydrogenated product (A) of the conjugated diene polymer polyol other than the hydroxyl groups at both ends. Y represents the residue of the second part, i.e., the polyisocyanate (B), and more specifically, represents the part of the polyisocyanate (B) other than the isocyanate groups at both ends. Multiple Ys may be the same or different. The third part is bonded to both ends of formula (2). The third part is the residue of the hydroxyl-containing aromatic vinyl compound (C), and is the part of the hydroxyl-containing aromatic vinyl compound (C) other than the hydroxyl groups.

[0055] In formula (2), n is an integer greater than 1. n represents the number of repetitions of the bonding between the first part and the second part, and molecules with different n may be mixed. Preferably n=1, and molecules with n greater than 2 may also be included. The upper limit of n is not particularly limited, and may be, for example, 20 or less.

[0056] According to the above, the vinyl-containing prepolymer of formula (2) is a vinyl compound containing a carbamate bond having a structure in which the second part is bonded to both ends of the first part via a carbamate bond, and the third part is bonded to both ends of the second part via a carbamate bond, respectively. The first part and the second part may be bonded alternately and repeatedly for multiple times, or may be a mixture of different numbers of repetitions.

[0057] The number average molecular weight (Mn) of the vinyl group-containing prepolymer is not particularly limited, and may be, for example, 1,000 to 50,000, or 2,000 to 20,000.

[0058] The vinyl-containing prepolymer has a vinyl group and thus exhibits curability that can be cured by addition polymerization using heat, light, etc. Therefore, the curable resin composition of the embodiment includes the vinyl-containing prepolymer. In one embodiment, the curable resin composition is preferably a thermosetting resin composition that is cured by heat.

[0059] The curable resin composition may contain the vinyl monomer copolymerizable with the vinyl prepolymer. As the vinyl monomer, a monofunctional (i.e., one vinyl group) vinyl monomer may be used as a diluent, or a difunctional or higher (i.e., one having multiple vinyl groups) vinyl monomer may be used as a crosslinking agent.

[0060] Examples of monofunctional vinyl monomers include styrene, chlorostyrene, butylstyrene, acrylic acid, methacrylic acid, ethyl acrylate, methyl methacrylate, acrylonitrile, vinyl pyrrolidone, and vinyl acetate. Examples of difunctional or higher-functional vinyl monomers include divinylbenzene and 1,5-hexadiene.

[0061] The curable resin composition may further contain various components such as fillers such as inorganic fillers, thermoplastic resins, flame retardants, curing accelerators, polymerization initiators, defoamers, heat stabilizers, antistatic agents, ultraviolet absorbers, colorants such as dyes and pigments, lubricants, dispersants, etc.

[0062] In addition, the curable resin composition may contain an organic solvent to adjust its viscosity, and the curable resin composition may also be a solution containing the above-mentioned vinyl-containing prepolymer. As the organic solvent, one that can dissolve the above-mentioned vinyl-containing prepolymer is used, for example, ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, esters such as ethyl acetate, propyl acetate, and butyl acetate, amides such as dimethylacetamide and dimethylformamide, aromatic hydrocarbons such as toluene and xylene, etc., any one of these can be used or two or more of them can be used in combination.

[0063] Examples of the polymerization initiator include organic peroxides such as di-tert-butyl peroxide, tert-butyl hydroperoxide, and benzoyl peroxide, free radical initiators such as azo compounds such as azobisisobutyronitrile, and photoinitiators such as benzophenone and acetophenone. The amount of the polymerization initiator is not particularly limited, and may be, for example, 0.01 to 10 parts by mass relative to 100 parts by mass of the vinyl-containing prepolymer.

[0064] The above-mentioned vinyl-containing prepolymer has a low dielectric loss tangent and a low dielectric constant relative to high-frequency electrical signals, that is, it has excellent dielectric properties when used in applications utilizing high-frequency electrical signals. Therefore, the curable resin composition containing the above-mentioned vinyl-containing prepolymer is preferably used for insulation applications relative to high-frequency electrical signals, that is, for high-frequency insulating materials. In addition, the so-called high frequency refers to 1 GHz or more, and more preferably 3 GHz to 80 GHz.

[0065] The high-frequency insulating material is not particularly limited, and examples thereof include materials used to form a printed circuit board (high-frequency printed circuit board) used for transmission of high-frequency signals, and materials constituting any layer (insulating layer) of the high-frequency printed circuit board.

[0066] Example

[0067] Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples, but the present invention is not limited thereto.

[0068] The details of the conjugated diene polymer polyol used in the examples are as follows.

[0069] ･Hydrogenated polybutadiene diol (1): Krasol HLBH-P3000 manufactured by Cray Valley Co., Ltd., number average molecular weight: 3000, 1,2-bond content: 65 mol%, number of functional groups: 1.9, hydroxyl value: 36 mgKOH / g, iodine value: 7 g / 100 g

[0070] ･Hydrogenated polybutadiene diol (2): Krasol HLBH-P2000 manufactured by Cray Valley Co., Ltd., number average molecular weight: 2000, 1,2-bond content: 65 mol%, number of functional groups: 1.9, hydroxyl value: 53 mgKOH / g, iodine value: 8 g / 100 g

[0071] ･Hydrogenated polybutadiene diol (3): "NISSO-PB GI-3000" manufactured by Nippon Soda Co., Ltd., number average molecular weight: 3100, number of functional groups: 2.0, hydroxyl value: 36 mgKOH / g, iodine value: 5 g / 100 g

[0072] ･Hydrogenated polyisoprene glycol (4): "EPOL" manufactured by Idemitsu Kosan Co., Ltd., number average molecular weight: 2500, 1,2-bond content: 20 mol%, number of functional groups: 2.0, hydroxyl value: 45 mgKOH / g, iodine value: 7 g / 100 g

[0073] ･Polybutadiene diol (5): "Polybd R45HT" manufactured by Idemitsu Kosan Co., Ltd. (number average molecular weight: 2800, number of functional groups: 2.0, hydroxyl value: 40 mgKOH / g)

[0074] [Example 1]

[0075] Into a four-necked flask equipped with a stirrer, a reflux cooling tube and a thermometer, 300 g (0.1 mol) of hydrogenated polybutadiene diol (1), 44.4 g (0.2 mol) of isophorone diisocyanate (IPDI) and 0.04 g of dioctyltin laurate were placed, and reacted at 50°C to 80°C for 3 hours. Next, 29.52 g (0.22 mol) of 4-vinylbenzyl alcohol (VBA) was added, and the reaction was further carried out at 50°C to 80°C until the amount of free isocyanate reached 0.1% by mass or less. Thus, a vinyl-containing prepolymer of Example 1 was obtained. The number average molecular weight Mn of the obtained vinyl-containing prepolymer measured by the above-mentioned GPC method was 4500.

[0076] [Example 2]

[0077] Into a four-necked flask equipped with a stirrer, a reflux cooling tube and a thermometer, 200 g (0.1 mol) of hydrogenated polybutadiene diol (2), 44.4 g (0.2 mol) of isophorone diisocyanate and 0.03 g of dioctyltin laurate were placed, and reacted at 50° C. to 80° C. for 3 hours. Next, 29.52 g (0.22 mol) of 4-vinylbenzyl alcohol was added, and the reaction was further carried out at 50° C. to 80° C. until the amount of free isocyanate reached 0.1% by mass or less, thereby obtaining a vinyl-containing prepolymer of Example 2. The number average molecular weight Mn of the obtained vinyl-containing prepolymer measured by the above-mentioned GPC method was 3500.

[0078] [Example 3]

[0079] Into a four-necked flask equipped with a stirrer, a reflux cooling tube and a thermometer, 310 g (0.1 mol) of hydrogenated polybutadiene diol (3), 44.4 g (0.2 mol) of isophorone diisocyanate and 0.04 g of dioctyltin laurate were added and reacted at 50° C. to 80° C. for 3 hours. Next, 29.52 g (0.22 mol) of 4-vinylbenzyl alcohol was added and further reacted at 50° C. to 80° C. until the amount of free isocyanate reached 0.1% by mass or less, thereby obtaining a vinyl-containing prepolymer of Example 3. The number average molecular weight Mn of the obtained vinyl-containing prepolymer measured by the above-mentioned GPC method was 4600.

[0080] [Example 4]

[0081] Into a four-necked flask equipped with a stirrer, a reflux cooling tube, a thermometer, and a nitrogen blowing tube, 250 g (0.1 mol) of hydrogenated polyisopentyl glycol (4), 44.4 g (0.2 mol) of isophorone diisocyanate, and 0.03 g of dioctyltin laurate were placed, and reacted at 50° C. to 80° C. for 3 hours. Next, 29.52 g (0.22 mol) of 4-vinylbenzyl alcohol was added, and the reaction was further carried out at 50° C. to 80° C. until the amount of free isocyanate reached 0.1% by mass or less, thereby obtaining a vinyl-containing prepolymer of Example 4. The number average molecular weight Mn of the obtained vinyl-containing prepolymer measured by the above-mentioned GPC method was 3800.

[0082] [Example 5]

[0083] Into a four-necked flask equipped with a stirrer, a reflux cooling tube and a thermometer, 300 g (0.1 mol) of hydrogenated polybutadiene diol (1), 33.6 g (0.2 mol) of hexamethylene diisocyanate (HDI) and 0.04 g of dioctyltin laurate were placed, and reacted at 50° C. to 80° C. for 3 hours. Next, 29.52 g (0.22 mol) of 4-vinylbenzyl alcohol was added, and the reaction was further carried out at 50° C. to 80° C. until the amount of free isocyanate became 0.1% by mass or less, thereby obtaining a vinyl-containing prepolymer of Example 5. The number average molecular weight Mn of the obtained vinyl-containing prepolymer measured by the above-mentioned GPC method was 5500.

[0084] [Example 6]

[0085] Into a four-necked flask equipped with a stirrer, a reflux cooling tube and a thermometer, 300 g (0.1 mol) of hydrogenated polybutadiene diol (1), 52.47 g (0.2 mol) of dicyclohexylmethane 4,4'-diisocyanate (hydrogenated MDI), and 0.04 g of dioctyltin laurate were placed, and reacted at 50°C to 80°C for 3 hours. Next, 29.52 g (0.22 mol) of 4-vinylbenzyl alcohol was added, and the reaction was further carried out at 50°C to 80°C until the amount of free isocyanate became 0.1% by mass or less, thereby obtaining a vinyl-containing prepolymer of Example 6. The number average molecular weight Mn of the obtained vinyl-containing prepolymer measured by the above-mentioned GPC method was 5500.

[0086] [Example 7]

[0087] Into a four-necked flask equipped with a stirrer, a reflux cooling tube and a thermometer, 300 g (0.1 mol) of hydrogenated polybutadiene diol (1), 30.8 g (0.2 mol) of 1,5-pentane diisocyanate and 0.04 g of dioctyltin laurate were placed, and reacted at 50° C. to 80° C. for 3 hours. Next, 29.52 g (0.22 mol) of 4-vinylbenzyl alcohol was added, and the reaction was further carried out at 50° C. to 80° C. until the amount of free isocyanate became 0.1% by mass or less, thereby obtaining a vinyl-containing prepolymer of Example 7. The number average molecular weight Mn of the obtained vinyl-containing prepolymer measured by the above-mentioned GPC method was 5500.

[0088] [Comparative Example 1]

[0089] Into a four-necked flask equipped with a stirrer, a reflux cooling tube, a thermometer and a dropping device, 280 g (0.1 mol) of polybutadiene diol (5), 280 g of toluene, and 20.2 g (0.2 mol) of triethylamine were placed, and 19.91 g (0.22 mol) of acryloyl chloride was added dropwise over a period of 1 hour. After the addition was completed, the reaction was carried out at room temperature for 1 hour. 50 g of isopropanol and 150 g of ion exchange water were added to the reaction solution, and the mixture was stirred and allowed to stand, and the separated water layer was removed. Next, the solvent was removed under reduced pressure to obtain a prepolymer of Comparative Example 1. The number average molecular weight Mn of the obtained prepolymer measured by the above-mentioned GPC method was 3200.

[0090] [Comparative Example 2]

[0091] Into a four-necked flask equipped with a stirrer, a reflux cooling tube and a thermometer, 280 g (0.1 mol) of polybutadiene diol (5), 44.4 g (0.2 mol) of isophorone diisocyanate and 0.04 g of dioctyltin laurate were added and reacted at 50° C. to 80° C. for 3 hours. Next, 29.52 g (0.22 mol) of 4-vinylbenzyl alcohol was added and further reacted at 50° C. to 80° C. until the amount of free isocyanate became 0.1% by mass or less, thereby obtaining a vinyl-containing prepolymer of Comparative Example 2. The number average molecular weight Mn of the obtained vinyl-containing prepolymer measured by the above-mentioned GPC method was 4200.

[0092] [Comparative Example 3]

[0093] Into a four-necked flask equipped with a stirrer, a reflux cooling tube and a thermometer, 300 g (0.1 mol) of hydrogenated polybutadiene diol (1), 34.84 g (0.2 mol) of toluene diisocyanate (TDI) and 0.04 g of dioctyltin laurate were placed, and reacted at 50° C. to 80° C. for 3 hours. Next, 29.52 g (0.22 mol) of 4-vinylbenzyl alcohol was added, and the reaction was further carried out at 50° C. to 80° C. until the amount of free isocyanate became 0.1% by mass or less, thereby obtaining a vinyl-containing prepolymer of Comparative Example 3. The number average molecular weight Mn of the obtained vinyl-containing prepolymer measured by the above-mentioned GPC method was 5000.

[0094] [Comparative Example 4]

[0095] Into a four-necked flask equipped with a stirrer, a reflux cooling tube and a thermometer, 300 g (0.1 mol) of hydrogenated polybutadiene diol (1), 44.4 g (0.2 mol) of isophorone diisocyanate and 0.04 g of dioctyltin laurate were charged and reacted at 50° C. to 80° C. for 3 hours. Next, 25.52 g (0.22 mol) of 2-hydroxyethyl acrylate was added and further reacted at 50° C. to 80° C. until the amount of free isocyanate became 0.1% by mass or less, thereby obtaining a prepolymer of Comparative Example 4. The number average molecular weight Mn of the obtained prepolymer measured by the above-mentioned GPC method was 4500.

[0096] The dielectric properties (dielectric constant Dk, dielectric loss tangent Df) and cured film properties (glass transition temperature Tg, strength, elongation) of each prepolymer of Examples 1 to 7 and Comparative Examples 1 to 4 obtained as described above were measured. The measurement methods are as follows.

[0097] [Production of Cured Material]

[0098] 0.05 g of a thermal polymerization initiator ("Pabuchiru P" manufactured by NOF Corporation) was mixed and dissolved in 10 g of each of the above prepolymers. 1.5 g of the sample was pressed for 5 minutes at a pressure of 10 Pa and a temperature of 200°C using a single-action compression molding machine for testing (manufactured by Yasuda Seiki Co., Ltd.) to prepare a flat plate of 40 mm×40 mm×1 mm in thickness.

[0099] [Dielectric constant, dielectric loss tangent]

[0100] The flat plate obtained above was cut into a test piece with a width of 2 mm, a thickness of 1 mm, and a length of 40 mm. The dielectric constant Dk and the dielectric loss tangent Df at 10 GHz were measured for the test piece using a cavity resonator dielectric constant measuring apparatus (manufactured by KEYSIGHT).

[0101] [Glass transition temperature Tg]

[0102] In the determination of the glass transition temperature, a dynamic viscoelasticity measuring device (manufactured by UBM Co., Ltd., model: Rheogel-E4000) was used. The flat plate obtained above was cut to make a test piece with a width of 2 mm, a thickness of 1 mm, and a length of 40 mm. For this test piece, the maximum value of the loss tangent (tanδ) measured under the conditions of tensile sine wave, frequency of 1 Hz, and temperature rise measurement of 3°C / min was obtained as the glass transition temperature.

[0103] [Strength, elongation]

[0104] A universal material testing machine (manufactured by A&D Co., Ltd., model: RTC-1225A) was used for the determination of strength and elongation. The flat plate obtained above was cut to produce a test piece with a width of 5 mm, a thickness of 1 mm, and a length of 40 mm. For this test piece, a tensile test was performed at a speed of 50 mm / min in accordance with JIS C2151:2019 to determine the tensile strength (stress at break) and elongation at break.

[0105] [Table 1]

[0106]

[0107] [Table 2]

[0108]

[0109] The results are shown in Tables 1 and 2. In the prepolymer of Comparative Example 1, acryloyl chloride was reacted at both ends of the non-hydrogenated polybutadiene diol. In Comparative Example 1, the dielectric loss tangent was high and the dielectric properties were poor. In addition, the strength and elongation were low and the physical properties of the cured film were poor. Furthermore, the glass transition temperature Tg was low and the heat resistance was poor.

[0110] In the vinyl-containing prepolymer of Comparative Example 2, a hydroxyl-containing aromatic vinyl compound is reacted at both ends of non-hydrogenated polybutadiene diol via an alicyclic polyisocyanate. In Comparative Example 2, the dielectric loss tangent is high and the dielectric properties are poor. In addition, the strength is low, and the glass transition temperature Tg is low.

[0111] In the vinyl-containing prepolymer of Comparative Example 3, a hydroxyl-containing aromatic vinyl compound is reacted at both ends of hydrogenated polybutadiene diol via an aromatic polyisocyanate. In Comparative Example 3, the dielectric constant and dielectric loss tangent are high, and the dielectric properties are poor. In addition, the elongation is low, and the physical properties of the cured film are poor.

[0112] In the prepolymer of Comparative Example 4, hydroxyl-containing acrylate was reacted at both ends of hydrogenated polybutadiene diol via aliphatic polyisocyanate. In Comparative Example 4, the dielectric constant and dielectric loss tangent were high, and the dielectric properties were poor.

[0113] In contrast, in the vinyl-containing prepolymers of Examples 1 to 7, the hydroxyl-containing aromatic vinyl compound is reacted at both ends of hydrogenated polybutadiene diol or hydrogenated polyisoprene diol via aliphatic polyisocyanate or alicyclic polyisocyanate. In the case of Examples 1 to 7, the dielectric constant and dielectric loss tangent are low, and the dielectric properties are excellent. In addition, compared with Comparative Example 1, the glass transition temperature Tg is high, and the strength and elongation are high, and the cured film properties are excellent.

[0114] Furthermore, the various numerical ranges described in the specification can be arbitrarily combined with the upper and lower limits thereof, and all of these combinations are described in the specification as preferred numerical ranges. In addition, the description of the numerical range "X to Y" means greater than X and less than Y.

[0115] Several embodiments of the present invention have been described above, but these embodiments are provided as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the scope of the invention. These embodiments or their omissions, substitutions, and changes are included in the scope or purpose of the invention, and are also included in the invention described in the scope of the patent application and its equivalent.

Claims

1. A vinyl-containing prepolymer, characterized in that The invention comprises: a first part, wherein the first part is derived from a hydrogenated product of a conjugated diene polymer polyol; and a second part, wherein the second part is derived from at least one polyisocyanate selected from aliphatic polyisocyanate and alicyclic polyisocyanate; and a third part, the third part being derived from a hydroxyl-containing aromatic vinyl compound, The vinyl-containing prepolymer has a vinyl group at the end, and the vinyl-containing prepolymer has the following structure: the first part and the second part are bonded via a urethane bond formed by the reaction of the hydroxyl group of the hydride and the isocyanate group of the polyisocyanate, and the second part and the third part are bonded via a urethane bond formed by the reaction of the isocyanate group of the polyisocyanate and the hydroxyl group of the hydroxyl-containing aromatic vinyl compound.

2. The vinyl-containing prepolymer according to claim 1, wherein The number average molecular weight of the hydrogenated product of the conjugated diene polymer polyol is 500 to 5,000.

3. The vinyl-containing prepolymer according to claim 1, wherein The hydrogenated product of the conjugated diene polymer polyol is hydrogenated polybutadiene polyol and / or hydrogenated polyisoprene polyol.

4. The vinyl-containing prepolymer according to claim 1, wherein The hydroxyl-containing aromatic vinyl compound is a compound represented by the following general formula (1): R in formula (1) 1 represents an alkanediyl group having 1 to 4 carbon atoms, R 2 represents an alkyl group having 1 to 4 carbon atoms, and p represents an integer of 0 to 4. [Chemistry 1] 。 5 . A curable resin composition comprising the vinyl-containing prepolymer according to claim 1 .

6. The curable resin composition according to claim 5, wherein Used for high frequency insulation materials.

7. A cured product obtained by curing the curable resin composition according to claim 5.

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